I don't know if anyone has ever mentioned this but it just occurred to me that in ASIB after the client with the broken down car faints in 221B Mrs. Hudson calls for Sherlock and John who are presumably in John's room. Later when we see Sherlock he is naked with a sheet around him. I don't think he got undressed after the client arrived so does that mean he was in John's room naked?!
This actually has been discussed before by various bloggers. Some think he and John were there together, others think it was just Sherlock.
I say this time and again: I believe all Hudders was doing was just simply yelling over her shoulder in the general direction of their rooms. To me that’s no indication on whether they were both sharing a room; even if they both were home, John could be in his and Sherlock in his. Plus, John says he “was in Dublin yesterday”, leading me to suspect that John was actually on out of London when this scene occurs. I actually think Sherlock was probably talking to his MP!John (“do you just carry on talking while I’m away?”) and maybe Mrs Hudson mistook that for Sherlock’s regular chatting with John at the flat, since John probably rarely speaks while Sherlock is rambling.
John in ASiB during the client scene is quietly in the background. Not taking notes like he normally does (at least it doesn’t look like he is), and the client doesn’t even acknowledge John being there (the clients usually turn to talk to John when they’re telling a story). And look what he’s wearing:
The same outfit as the John that I think we have mostly agreed is from Sherlock’s mind palace in TSo3. Which he’s not wearing on supposedly the same day that the client came in to talk to them:
ARGUABLY, it could be John took off the cardigan, so I will concede that, but it’s not like John to just… shuck his cardigans. So I think Sherlock kept talking to the MP John about not going out to the case because it’s not a 7, and then decided that he would get real John to go for him.
Anyway, to me, Sherlock called John away from his Dublin trip (probably with a girlfriend) to go to the crime scene, since he was already out and Sherlock in a fit of stroppiness wanted to flirt with John in the same way he’s probably seen John’s girlfriends flirt with him, so texts John to get to Dublin, hops in the shower, takes a nap and then when John texts him he’s there, sets up a skype call. In a sheet, so John knows what he’s missing when he’s not there. Because Sherlock is a silly and jealous man.
Now the part that has always confused me was whether or not the client was actually there or if Sherlock was mind-palacing him… I’m thinking the latter simply because the client just… disappears when they go to Buckingham, so I think Sherlock took the details of the client’s case, then ran him out so he could video chat with John, but he recalls the client in his MP, for whatever reason (perhaps as that niggling voice that’s chastising him for not being nicer in informing the client about his heart condition?).
ANYWAY, that was a really convoluted way to answer your questions, but no, I think Sherlock was coming from his own room after a nap and maybe a shower. There was definitely some time that passed here.